| closely | 2 | degree |
| melatonin → be made from → serotonin | 10 |
| melatonin → be linked to → serotonin | 3 |
| melatonin → be → serotonin-derived hormone | 3 |
| negative | neutral | positive |
| 0.118 | 0.613 | 0.269 |
| Raw frequency | 16 |
| Normalized frequency | 0.291 |
| Modifier score | 0.500 |
| Perplexity | 25.193 |